In frames where the light is doing work on the mirror (the light is speeding it up), the exiting beam appears redshifted compared to the solar beam, and in frames where the mirror is doing work on the light (the light is slowing it down) the exiting beam appears blueshifted compared to the solar beam. Strange stuff, but it all works out so that energy appears to be conserved from every point of view.
The problem is that most people will say something like, "Yeah, some people are impaired, but not me. I'd know." Actually, you don't necessarily know when you're impaired. If you were on the ball enough to notice, you wouldn't be impaired. If you are lucky, you'll notice some secondary effect of being impaired ("Hmmm... why does traffic always get hairy when I'm on the phone?"), and (when you're not on the phone) make the connection.
I remember something similar happening to me with alcohol, back when I drove a motorcycle. I'm no lightweight, but I noticed that even ONE drink with supper would affect my ability to hold a particular line on mountain roads -- even when I didn't feel impaired at all. Ever after, I held to an "eight-hour rule", just like pilots.
Nope, the solar wind actually doesn't carry nearly as much momentum as the light itself. But you can tack a solar sail by tilting the mirror so that the exit beam shines in different directions. The thrust from the sail is the vector difference between the incoming and outgoing beam directions, times the total amount of sunlight power you're reflecting.
I think we're in agreement here -- except that microwave heating can't suddenly inject lots of energy into a single atom. Once the atom breaks its bonds to the rest of the paint, it's no longer coupled to the rest of the paint, so it's not receiving any more energy from the microwave beam. So all you get is the kinetic energy the atom gains as it comes down from the potential barrier that normally prevents dissociation.
Ion engines do have chemical bonds to break: they work using a stream of lone ions, which are generally delivered at the launch pad as part of a bulk material. But the bond energy is a tiny fraction of the total energy. Er, I think we're saying the same thing about the ions, just slightly differently.
Several folks (including me) have called out the problems with multiple streamers and buffer lag. I have such a system in my house (except with a custom juke engine instead of gnumpd3), and find that it doesn't do what the poster wants -- stream simultaneously throughout the house. The problem is that different instances of xmms don't stay synchronized to better than about a second or so, so you get weird echo effects throughout the house. Not good.
Yes, gnump3d/icecast/xmms is a good solution for accessing your collection. No, it's not a complete solution for playing music throughout the house. For that you have to add a multichannel stereo.
We have a music streaming server in a closet with a wireless base station. Fresh, configurable music streamed throughout the house on-demand. Nice. but: playing the same stream on multiple computers is AWFUL, because the computers inevitably end up out of synch. Even a quarter second is awful, but it can get as bad as a second or two. The issue is that stream clients have to fudge the stream to stay synchronized, and inevitably different clients fudge in different ways. Since most streamers keep a 5-10 second buffer, in principle your different rooms can get up to that far out of synch, giving you an awful echo effect.
If you must go wireless, use one of the wireless-speaker solutions like they advertise in Popular Science, where the sound is sent as FM radio throughout the house.
That's correct -- the energy isn't coming directly from chemical bonds -- but it's still difficult to make the molecules leave with more energy than is contained in the bonds holding them in place. The issue is that, once they obtain sufficient energy to escape, they do so. In order to put any more energy on onto the propellant, you have to somehow keep interacting with it after it already has obtained the escape energy.
Ion rockets do this by putting an electrical potential on the propellant mass. Then when a freshly ionized propellant molecule leaves the engine, it is electrostatically repulsed from the back of the engine (and perhaps attracted by the exit grid). That repulsion is what imparts the final "kick" to it. It's the same technology that makes old-style television sets and other particle accelerators work.
But this paint scheme has no such macroscopic design -- from the article, it sounds like they're just trying to heat it fast with microwaves.
The sail is being used as a rocket engine. That is not too helpful, as the exhaust speed of the paint is still limited by chemical bonds (it's hard to make individual paint molecules leave with more kinetic energy than is contained in a chemical bond). That means you would need just as much propellant (in the form of paint) for this scheme as you would need for a normal chemical rocket engine.
These guys are definitely on an interesting track, though. The problem with rocket engines in general is that they have a tradeoff between mass efficiency (you want to put as much momentum on each piece your propellant as possible, so that you get as much push from it as possible) and energy efficiency (it costs energy to push propellant, and you have to supply the energy).
Chemical rockets can't get much more efficient than the Space Shuttle Main Engines, because the amount of energy available for each molecule of exhaust gas is whatever you can get by chemically reacting your fuel to make the propellant molecule. The SSMEs use one of the most energetic-per-unit-mass chemical reactions around: hydrogen and oxygen (fuels) combining to make water (propellant).
Electric ion rockets do better because each molecule of propellant gets much more energy than would be available from chemical reactions. The problem there is that you still have to produce the energy. Nuclear electric propulsion uses plutonium to generate heat, which is converted to electricity and then used to run the ion rocket. Solar electric propulsion uses solar panels to generate electricity that runs the ion rocket. The problem is that both of those schemes are limited by the power available: it's hard to make energy rapidly with either a conventional radiothermal (noncritical) generator or solar panels, so while the rocket is extremely fuel efficient it is also quite slow.
Pure solar sails use the best/worst propellant in the Universe: photons. Best, because photons are disposable -- "use all you want, we'll make more!". Worst, because photons use the most energy per unit delivered momentum of any propellant in the universe. So a sail transduces huge amounts of power (at least in the inner solar system) but uses a very inefficient process to convert that energy to momentum.
Making the sail into a hybrid rocket is a Good thing, but using this paint scheme doesn't help, because the ejected molecules don't ever get much more energy than their own chemical binding energy into the paint -- that means they're being more or less wasted as propellant, because you want to put as much kinetic energy on the propellant as possible.
A better scheme is to use a curved solar sail as a concentrator to heat up a high power electrical generator, and then use the electricity to drive an ion rocket. In 2000 or 2001 I and a colleague worked up the numbers for such a scheme (there are technical problems with making high-power ion rockets; but we considered just energy flow). A smallish curved solar sail (say, 120m in diameter) can concentrate 10 megawatts of heat onto a heat collector. At 10% conversion efficiency to propellant power (15% for conversion to electricity, times 67% efficiency in the rocket engine) that would still be a megawatt of power, enough to provide hundreds or thousands of Newtons of thrust. In several scenarios we considered, the acceleration of the whole craft is higher than the unloaded self-acceleration of the sail, so it would be necessary to repel the sail electrostatically or something like that to keep its shape correct.
Ion rockets can be 100 to 1000 times more propellant-efficient than chemical rockets, provided that there is enough energy available.
Requiring that a second shuttle be ready for rescue operations is certainly a feasible way to reduce risk of re-entry failure; but doing so for the first few launches seems to be to be a waste of resources. The probability of catastrophic tile damage must always have been small, or the shuttle wouldn't have flown so many times before the first mishap. Flying for a few times with rescue backup, and then stopping, gives everyone a nice fuzzy feeling about the return to flight -- and then permits returning to "business as usual", without the extra protection a rescue plan would afford. That's PHB thinking...
Even if tile damage isn't observed on the first few flights, the underlying problem -- the great fragility of the leading edges -- remains, and we can't even estimate well how bad the risk is until at least the first rescue mission is flown - i.e. for something like another hundred missions. (I know, there are a priori ways to assess risk, but given the shenanigans the manned program management is known to pull, do you trust their a priori figures? Didn't think so...)
... are available right now at Costco. It blew me away -- there's a separate feed for putting your disk in the printer, and it prints your image on the textured label side of the disk.
Magnetohydrodynamics is the subject of how magnetic fields and plasmas interact. Plasma is the most common state of matter in the Universe -- a soup of positive ions and negative electrons. But we still can't model its behavior worth a damn. The problem is that the classical equations lead to singularities: some kinds of feature (like electric currents) tend to squeeze themselves into narrow ribbons that are "infinitely" thin. In nature, these "current sheets" aren't actually infinitely thin -- but they're pretty tiny.
On our Sun, a solar active region might be about the size of Jupiter, but it's controlled by the behavior of current sheets that are only a few meters across!
The problem is that cross-scale coupling like that really eats computing resources, because a volume that is n pixels across generally takes O(n^4) computing cycles.
True understanding of astrophysical plasmas (like the Sun, our Earth's space environment, the interstellar medium, or supernovae) and laboratory plasmas (like fusion generators) will require some kind of major breakthrough in simulation technique and/or computing power.
Re:Grade dilution, playpens, party animals
on
Who Needs Harvard?
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· Score: 1
Funny you should compare Astronomy to Underwater Basketweaving. UB is derided as a non-intellectual course, and indeed it is -- UB is largely about learning a manual skill. It's a useless course for most people because (A) most basket-weavers are overseas; and (B) basket-weaving doesn't require any particular mental skill that you can't pick up some other way.
Astronomy on the other hand, at least in ASTR 101 or its equivalent, is mostly about critical thinking. Sure, there are some facts to be learned (why the seasons happen, general structure of the solar system, etc.). But by far the most important skill in that course is critical thinking -- how to recognize when data conflict with your preconceptions, and what to do about it. The same may be said of other introductory science courses. Properly taught, they are about the highly successful scientific method of thinking, rather than "merely" about the particular field mentioned in the catalog.
That is why most schools still require a couple of science courses as part of the "core curriculum".
Likewise, why do engineers and physicists have to take literature and economics courses? Because they teach communication and business ideas that come in handy in any field.
But my original rant was more about the fact that many students are able to cruise through college without learning very much. At the end, the result is college graduates who can't sort truth from sales propaganda, who can't think clearly about the consequences of their own actions, or who can't write two coherent sentences back-to-back. That devalues the academic credentials those students carry.
It is I who owe you the apology, for not understanding the nuances of your meaning. Please forgive my arrogance in assuming you did not know what you were saying.
Grade dilution, playpens, party animals
on
Who Needs Harvard?
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· Score: 3, Insightful
I teach astronomy at the college level at a large state school, and I did my graduate work (including TAing) at Stanford. I'm continually amazed at just how, well, crappy most students are. Because there are such big financial incentives to finish college, many people go to college who simply don't belong there.
I refer to people who don't enjoy learning, who prefer not to think, who generally don't retain what little they do learn, and who often don't pick up the infrastructural skill of critical, organized thinking.
These people are suffered to finish because the schools and departments themselves have incentives to process as many people as possible.
IMHO, that has devalued higher degrees and academic grades so far that they aren't helpful predictors of future performance. We're seeing that reflected in the Fortune 100 statistics.
If you want to get employment/government money, you are judget by peers with better credentials.
Not true. I make my living that way, and as part of my work as a scientist, I occasionally help to review articles for journals or sit on review panels for funding proposals to NASA. Those panels are not full of idiots, by any means -- but the people conducting the reviews are generally not any more senior or experienced than the people submitting the articles or proposing new research.
WP lets everyone edit (nearly) every page.... [so] the quality of WP will converge to the mean of all users, a college education (considering that people with less skills pro'lly won't edit).
No, actually, that argument applies very well to the demise of USENET in the 1990s but not to Wikipedia. In the 1990s, America Online and other ISPs gave exponentially increasing numbers of ordinary people access ot USENET, and most of the interesting unmoderated fora were drowned in a sea of mediocrity and the signal-to-noise ratio dropped to where USENET was no longer useful to professionals and academics.
While it is not (formally) moderated, Wikipedia is a different type of forum. Most individual posts don't clog up the medium the way that FAQs (the questions, not the lists of answers), contentious idiots, and spam clogged up USENET.
It remains to be seen whether the noise level will rise enough to drown out the signal, but as Wikipedia gains notoriety it seems to be scaling pretty well.
Yup. I'd definitely mod you up (Insightful) if I hadn't already posted in the thread.
Reminds me of a BoingBoing story a while ago about a guy who was crowing about the convenience using a wireless switch to control his garbage disposal. Works great until you stick your hand down there just as your neighbor tries out his wireless switch controlled garage door...
"Any programmer" doesn't have time to fix your bugs.... most people don't want to.... programmers have better things to do than wade through somebody else's horrible buggy code just to print a letter.
Well, sure. But FOSS wins by the very same effect that keeps spammers going. "Nobody" answers spam, but "nobody" is enough to keep at least some spammers going. If only one in a thousand users is willing and able to fix a particular class of bug, then an application with an installed base of 50,000 will have 50 people willing to hammer on at least one of those bugs.
I can't count the number of times I've waited six months and reloaded a crappy FOSS project to find all my major peeves fixed. LyX, GIMP, OpenOffice, Kontact, FireFox, Xine, and BlueFish are all examples.
I should say at this point that configuration problems are far more common on Linux and their solutions tend to be considerably more complicated and hard to find.
Hmmm. That hasn't been my experience at all. In general I use a mix of bleeding-edge and ancient hardware. It's true that it seems to take about six months before a bleeding-edge product gets a custom Linux driver, but OTOH Fedora, Mandrake, and even OpenBSD seem to find my USB drives, ATI graphics cards, NVIDIA on-board graphics chipsets, miscellaneous sound cards, dual CPUs, ancient SCSI scanners, DVD burners, PS/2 mice, USB mice, keyboards, trackpads, and parallel ZIP drives just fine, thank you. No configuration required.
On the other hand, I can't count the number of times my colleagues, wife, and friends have complained that installing some WidgetDriver 5.x gave them a semipermanent BSOD on a losedows machine. My wife manages IT for a Losedows business, and relies on frequent fresh system installs to keep everything running. I've NEVER had to re-install from scratch to repair any Linux system.
Subpoenas of source information at all levels of the journalistic hierarchy are causing trouble, lately. Even the New York Times has a couple of reporters in jail for not revealing their sources for stories on the Plame affair (remember, when one of the crooks in the White House illegally outed a deep-cover CIA agent in retribution for whistleblowing by her husband...).
It'll be interesting to see whether OPP, AI, and TS will stand their ground as firmly as the NYT did, or whether they roll over for the courts.
Actually, splitting the hair just a tiny bit finer would preserve the GPL while gutting commercial software licenses. Object code is not human readable, therefore it is better thought of as a device than as a form of expression, therefore, prima facie, it should not be copyrightable (IMHO, IANAL, SMC, HAND). Source code is human readable, therefore it is a better fit to the copyright code's intent of protecting expression.
Under that theory, the GPL would keep its teeth but (e.g.) the M$ EULA, which also relies on copyright law, would not. Of course, that won't happen in a million billion jillion years...
Sweet analogy, except that it's totally not applicable. Water molecules come rapidly into thermal equilibrium in liquid. The grandparent is just describing "ordinary" superheating, something that is especially easy to do with a microwave but that you can also accomplish with an ordinary stovetop and VERY CLEAN glassware.
Hmmm... I agree about the spreading of the beam -- I was implicitly hoping for a pretty tight beam coming from the distortion station. Let's see... suppose you had a 0.05-degree beam (not unreasonable in the X band; barely feasible in the Ku band), and the satellite is 300 miles away, and it's 3 meters in diameter. Then a 10MW transmitter would hit the satellite with about 1 kilowatt of energy (to be reflected or scattered), assuming you have pretty good steering on your beam.
So, er, I agree -- passive reflection jamming is probably marginally feasible for LEO satellites, and not at all for GEO satellites. I was wrong about comsats. Thanks!
Nah, a radiotelescope (in the context I'm using) is just a big high-gain antenna. Most of 'em are just parabolic dishes made of wire mesh. Anything longer wavelength than the size of the holes in the mesh gets reflected and either colimmated or focused (depending on which way you point it).
I said "radiotelescope" rather than "dish antenna" because one might want to use phased arrays rather than a physical antenna, these days...
Slashdot Mirror
In frames where the light is doing work on the mirror (the light is speeding it up), the exiting beam appears redshifted compared to the solar beam, and in frames where the mirror is doing work on the light (the light is slowing it down) the exiting beam appears blueshifted compared to the solar beam. Strange stuff, but it all works out so that energy appears to be conserved from every point of view.
I remember something similar happening to me with alcohol, back when I drove a motorcycle. I'm no lightweight, but I noticed that even ONE drink with supper would affect my ability to hold a particular line on mountain roads -- even when I didn't feel impaired at all. Ever after, I held to an "eight-hour rule", just like pilots.
Nope, the solar wind actually doesn't carry nearly as much momentum as the light itself. But you can tack a solar sail by tilting the mirror so that the exit beam shines in different directions. The thrust from the sail is the vector difference between the incoming and outgoing beam directions, times the total amount of sunlight power you're reflecting.
Ion engines do have chemical bonds to break: they work using a stream of lone ions, which are generally delivered at the launch pad as part of a bulk material. But the bond energy is a tiny fraction of the total energy. Er, I think we're saying the same thing about the ions, just slightly differently.
Yes, gnump3d/icecast/xmms is a good solution for accessing your collection. No, it's not a complete solution for playing music throughout the house. For that you have to add a multichannel stereo.
We have a music streaming server in a closet with a wireless base station. Fresh, configurable music streamed throughout the house on-demand. Nice. but: playing the same stream on multiple computers is AWFUL, because the computers inevitably end up out of synch. Even a quarter second is awful, but it can get as bad as a second or two. The issue is that stream clients have to fudge the stream to stay synchronized, and inevitably different clients fudge in different ways. Since most streamers keep a 5-10 second buffer, in principle your different rooms can get up to that far out of synch, giving you an awful echo effect.
If you must go wireless, use one of the wireless-speaker solutions like they advertise in Popular Science, where the sound is sent as FM radio throughout the house.
Ion rockets do this by putting an electrical potential on the propellant mass. Then when a freshly ionized propellant molecule leaves the engine, it is electrostatically repulsed from the back of the engine (and perhaps attracted by the exit grid). That repulsion is what imparts the final "kick" to it. It's the same technology that makes old-style television sets and other particle accelerators work.
But this paint scheme has no such macroscopic design -- from the article, it sounds like they're just trying to heat it fast with microwaves.
These guys are definitely on an interesting track, though. The problem with rocket engines in general is that they have a tradeoff between mass efficiency (you want to put as much momentum on each piece your propellant as possible, so that you get as much push from it as possible) and energy efficiency (it costs energy to push propellant, and you have to supply the energy).
Chemical rockets can't get much more efficient than the Space Shuttle Main Engines, because the amount of energy available for each molecule of exhaust gas is whatever you can get by chemically reacting your fuel to make the propellant molecule. The SSMEs use one of the most energetic-per-unit-mass chemical reactions around: hydrogen and oxygen (fuels) combining to make water (propellant).
Electric ion rockets do better because each molecule of propellant gets much more energy than would be available from chemical reactions. The problem there is that you still have to produce the energy. Nuclear electric propulsion uses plutonium to generate heat, which is converted to electricity and then used to run the ion rocket. Solar electric propulsion uses solar panels to generate electricity that runs the ion rocket. The problem is that both of those schemes are limited by the power available: it's hard to make energy rapidly with either a conventional radiothermal (noncritical) generator or solar panels, so while the rocket is extremely fuel efficient it is also quite slow.
Pure solar sails use the best/worst propellant in the Universe: photons. Best, because photons are disposable -- "use all you want, we'll make more!". Worst, because photons use the most energy per unit delivered momentum of any propellant in the universe. So a sail transduces huge amounts of power (at least in the inner solar system) but uses a very inefficient process to convert that energy to momentum.
Making the sail into a hybrid rocket is a Good thing, but using this paint scheme doesn't help, because the ejected molecules don't ever get much more energy than their own chemical binding energy into the paint -- that means they're being more or less wasted as propellant, because you want to put as much kinetic energy on the propellant as possible.
A better scheme is to use a curved solar sail as a concentrator to heat up a high power electrical generator, and then use the electricity to drive an ion rocket. In 2000 or 2001 I and a colleague worked up the numbers for such a scheme (there are technical problems with making high-power ion rockets; but we considered just energy flow). A smallish curved solar sail (say, 120m in diameter) can concentrate 10 megawatts of heat onto a heat collector. At 10% conversion efficiency to propellant power (15% for conversion to electricity, times 67% efficiency in the rocket engine) that would still be a megawatt of power, enough to provide hundreds or thousands of Newtons of thrust. In several scenarios we considered, the acceleration of the whole craft is higher than the unloaded self-acceleration of the sail, so it would be necessary to repel the sail electrostatically or something like that to keep its shape correct.
Ion rockets can be 100 to 1000 times more propellant-efficient than chemical rockets, provided that there is enough energy available.
Even if tile damage isn't observed on the first few flights, the underlying problem -- the great fragility of the leading edges -- remains, and we can't even estimate well how bad the risk is until at least the first rescue mission is flown - i.e. for something like another hundred missions. (I know, there are a priori ways to assess risk, but given the shenanigans the manned program management is known to pull, do you trust their a priori figures? Didn't think so...)
... are available right now at Costco. It blew me away -- there's a separate feed for putting your disk in the printer, and it prints your image on the textured label side of the disk.
On our Sun, a solar active region might be about the size of Jupiter, but it's controlled by the behavior of current sheets that are only a few meters across!
The problem is that cross-scale coupling like that really eats computing resources, because a volume that is n pixels across generally takes O(n^4) computing cycles.
True understanding of astrophysical plasmas (like the Sun, our Earth's space environment, the interstellar medium, or supernovae) and laboratory plasmas (like fusion generators) will require some kind of major breakthrough in simulation technique and/or computing power.
Astronomy on the other hand, at least in ASTR 101 or its equivalent, is mostly about critical thinking. Sure, there are some facts to be learned (why the seasons happen, general structure of the solar system, etc.). But by far the most important skill in that course is critical thinking -- how to recognize when data conflict with your preconceptions, and what to do about it. The same may be said of other introductory science courses. Properly taught, they are about the highly successful scientific method of thinking, rather than "merely" about the particular field mentioned in the catalog.
That is why most schools still require a couple of science courses as part of the "core curriculum".
Likewise, why do engineers and physicists have to take literature and economics courses? Because they teach communication and business ideas that come in handy in any field.
But my original rant was more about the fact that many students are able to cruise through college without learning very much. At the end, the result is college graduates who can't sort truth from sales propaganda, who can't think clearly about the consequences of their own actions, or who can't write two coherent sentences back-to-back. That devalues the academic credentials those students carry.
It is I who owe you the apology, for not understanding the nuances of your meaning.
Please forgive my arrogance in assuming you did not know what you were saying.
I refer to people who don't enjoy learning, who prefer not to think, who generally don't retain what little they do learn, and who often don't pick up the infrastructural skill of critical, organized thinking.
These people are suffered to finish because the schools and departments themselves have incentives to process as many people as possible.
IMHO, that has devalued higher degrees and academic grades so far that they aren't helpful predictors of future performance. We're seeing that reflected in the Fortune 100 statistics.
Careful -- your own ignorance is showing. Zen is but one type of buddhism, out of at least three.
Not true. I make my living that way, and as part of my work as a scientist, I occasionally help to review articles for journals or sit on review panels for funding proposals to NASA. Those panels are not full of idiots, by any means -- but the people conducting the reviews are generally not any more senior or experienced than the people submitting the articles or proposing new research.
No, actually, that argument applies very well to the demise of USENET in the 1990s but not to Wikipedia. In the 1990s, America Online and other ISPs gave exponentially increasing numbers of ordinary people access ot USENET, and most of the interesting unmoderated fora were drowned in a sea of mediocrity and the signal-to-noise ratio dropped to where USENET was no longer useful to professionals and academics.
While it is not (formally) moderated, Wikipedia is a different type of forum. Most individual posts don't clog up the medium the way that FAQs (the questions, not the lists of answers), contentious idiots, and spam clogged up USENET.
It remains to be seen whether the noise level will rise enough to drown out the signal, but as Wikipedia gains notoriety it seems to be scaling pretty well.
Reminds me of a BoingBoing story a while ago about a guy who was crowing about the convenience using a wireless switch to control his garbage disposal. Works great until you stick your hand down there just as your neighbor tries out his wireless switch controlled garage door...
Well, sure. But FOSS wins by the very same effect that keeps spammers going. "Nobody" answers spam, but "nobody" is enough to keep at least some spammers going. If only one in a thousand users is willing and able to fix a particular class of bug, then an application with an installed base of 50,000 will have 50 people willing to hammer on at least one of those bugs.
I can't count the number of times I've waited six months and reloaded a crappy FOSS project to find all my major peeves fixed. LyX, GIMP, OpenOffice, Kontact, FireFox, Xine, and BlueFish are all examples.
Hmmm. That hasn't been my experience at all.
In general I use a mix of bleeding-edge and ancient hardware. It's true that it seems to take about six months before a bleeding-edge product gets a custom Linux driver, but OTOH Fedora, Mandrake, and even OpenBSD seem to find my USB drives, ATI graphics cards, NVIDIA on-board graphics chipsets, miscellaneous sound cards, dual CPUs, ancient SCSI scanners, DVD burners, PS/2 mice, USB mice, keyboards, trackpads, and parallel ZIP drives just fine, thank you. No configuration required.
On the other hand, I can't count the number of times my colleagues, wife, and friends have complained that installing some WidgetDriver 5.x gave them a semipermanent BSOD on a losedows machine. My wife manages IT for a Losedows business, and relies on frequent fresh system installs to keep everything running. I've NEVER had to re-install from scratch to repair any Linux system.
So, er, I call bullshit. I know, IHBT. IWHAND.
Subpoenas of source information at all levels of the journalistic hierarchy are causing trouble, lately. Even the New York Times has a couple of reporters in jail for not revealing their sources for stories on the Plame affair (remember, when one of the crooks in the White House illegally outed a deep-cover CIA agent in retribution for whistleblowing by her husband...).
It'll be interesting to see whether OPP, AI, and TS will stand their ground as firmly as the NYT did, or whether they roll over for the courts.
Under that theory, the GPL would keep its teeth but (e.g.) the M$ EULA, which also relies on copyright law, would not. Of course, that won't happen in a million billion jillion years...
Sweet analogy, except that it's totally not applicable. Water molecules come rapidly into thermal equilibrium in liquid. The grandparent is just describing "ordinary" superheating, something that is especially easy to do with a microwave but that you can also accomplish with an ordinary stovetop and VERY CLEAN glassware.
Where? I could use a few. My Pentia are running too hot.
So, er, I agree -- passive reflection jamming is probably marginally feasible for LEO satellites, and not at all for GEO satellites. I was wrong about comsats. Thanks!
I said "radiotelescope" rather than "dish antenna" because one might want to use phased arrays rather than a physical antenna, these days...